Device and method for fast tuning terahertz parametric oscillation radiation source based on Rowland circle

Abstract

The invention provides a rapid tuning terahertz parametric oscillation radiation source device and method based on a rowland circle. The rapid tuning terahertz parametric oscillation radiation source device comprises a focusing lens set, a magnesium oxide-doped lithium niobate crystal, a first pump light high-reflectivity mirror, a second pump light high-reflectivity mirror, a first ring-shaped cavity mirror, a third ring-shaped cavity mirror, a second ring-shaped cavity mirror, a rotatable electronically-controlled galvanometer, a laser receiver and a computer, wherein the focusing lens set is provided with a laser, receives the emergent light of the laser, and is composed of a focusing convex lens and a focusing concave lens; the first ring-shaped cavity mirror is positioned on the reflection light paths of the second pump light high-reflectivity mirror and the rotatable electronically-controlled galvanometer; the third ring-shaped cavity mirror is positioned on the pump light reflection light path and the Stokes light emergent light path of the magnesium oxide-doped lithium niobate crystal; the second ring-shaped cavity mirror is positioned on the reflection light path of the third ring-shaped cavity mirror; the rotatable electronically-controlled galvanometer is positioned on the reflection light path of the second ring-shaped cavity mirror; the laser receiver is used for receiving the transmission light of the second ring-shaped cavity mirror; the computer is used for controlling the voltage on the rotatable electronically-controlled galvanometer. The rapid tuning terahertz parametric oscillation radiation source device and method can realize rapid frequency tuning and high-power stable output of terahertz waves.

Description

technical field [0001] The invention relates to a terahertz parametric oscillation radiation source. In particular, it relates to a fast-tuning terahertz parametric oscillation radiation source device and method based on the Rowland circle. Background technique [0002] Terahertz (Terahertz, referred to as THz, 1THz = 10 12 Hz) radiation source is the key core technology for the development of science and technology in the THz field. It refers to the frequency range from 100 GHz to 10 THz, the corresponding wavelength is from 3 mm to 30 microns, and the electromagnetic spectrum range is quite wide between millimeter wave and infrared light. . Due to its special position in the electromagnetic spectrum, it has a series of special properties. In particular, fast-tunable, high-power, narrow-linewidth THz coherent radiation sources have great potential in national and national defense security fields such as material science, solid-state physics, molecular analysis, atmospher...

AI Technical Summary

Problems solved by technology

When the Stokes optical resonator is fixed and the incident angle of the pump light is changed, the output frequency of the terahertz wave can be quickly tuned, but the position where the incident light enters the nonlinear crystal will change to a certain extent, which causes the pump light to The position of interaction with Stokes light in the nonlinear crystal changes, which affects the output power and conversion efficiency of THz waves, and has a certain impact on the collection and detection of THz waves

When the incident direction of the pump light is fixed and the angle of the entire Stokes resonator is changed to achieve tuning, since the Stokes optical resonator mirror and the lithium niobate crystal need to be rotated at the same time, this requires the entire platform to rotate and move, and the tuning speed is slow, which is difficult to meet Practical needs

[0004] In order to improve the output power and beam quality of the THz wave, the THz wave vertical lithium niobate crystal surface emitting cavity structure can effectively reduce the absorption of the THz wave generated by the lithium niobate crystal, but this scheme uses the rotation of the entire Stokes resonant cavity to achieve tuning. It fails to meet the needs of high power output (capable of room temperature detection) and fast frequency tuning at the same time, and has shortcomings such as difficult coupling pumping and slow tuning speed, which restricts its practical application in the field of scientific research and national defense security

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